Melhores Alunos

Parte da seção Lógica e fluxo do Journey de GDScript da Coddy. Lição 48 de 78.

Desafio

Fácil

Por fim, encontre os melhores alunos. Mantenha tudo o que você escreveu nas etapas anteriores.

1. A função. Abaixo das outras funções, escreva filter_top_students(threshold: float) -> Array. Ela retorna um array com os nomes dos alunos cuja nota média é maior que o limite, na ordem em que foram adicionados. Obtenha cada média com calculate_average_grade(); um aluno sem notas tem média 0.0.

2. O comando. Adicione um ramo para top <threshold>, como top 80, acima de ["show"]. Ele converte o limite com float() e imprime o array retornado por filter_top_students(). Para os comandos

add Alice 20 Math Physics
add Bob 22 Math Biology
add Diana 23 Chemistry Physics
grade Alice 90
grade Alice 85
grade Bob 75
grade Diana 95
top 80
top 90
top 100
exit

a saída é:

Student 'Alice' added successfully.
Student 'Bob' added successfully.
Student 'Diana' added successfully.
Grade 90 added for student 'Alice'.
Grade 85 added for student 'Alice'.
Grade 75 added for student 'Bob'.
Grade 95 added for student 'Diana'.
["Alice", "Diana"]
["Diana"]
[]
Goodbye!

Seu Student Records Manager agora combina dicionários, conjuntos, arrays, funções e match em um único programa.

Experimente você mesmo

extends Node

# Cada estudante: nome -> {"age": int, "grades": Array, "courses": um conjunto de nomes de cursos}
var student_records := {}

func _ready():
	while true:
		var parts := Array(OS.read_string_from_stdin().split(" ", false))
		match parts:
			["add", var student, var age, ..]:
				add_student(student, int(age), parts.slice(3))
			["grade", var student, var grade]:
				add_grade(student, int(grade))
			["enrolled", var student, var course]:
				print(is_enrolled(student, course))
			["average", var student]:
				var average := calculate_average_grade(student)
				if average >= 0:
					print("Average grade of '%s': %.2f" % [student, average])
			["course", var course]:
				print(list_students_by_course(course))
			["show"]:
				print(student_records)
			["exit"]:
				print("Goodbye!")
				break

func add_student(student_name: String, age: int, courses: Array) -> void:
	if student_records.has(student_name):
		print("Student '%s' already exists." % student_name)
		return
	var course_set := {}
	for course in courses:
		course_set[course] = true
	student_records[student_name] = {"age": age, "grades": [], "courses": course_set}
	print("Student '%s' added successfully." % student_name)

func add_grade(student_name: String, grade: int) -> void:
	if not student_records.has(student_name):
		print("Student '%s' not found." % student_name)
		return
	student_records[student_name]["grades"].append(grade)
	print("Grade %d added for student '%s'." % [grade, student_name])

func is_enrolled(student_name: String, course: String) -> bool:
	if not student_records.has(student_name):
		print("Student '%s' not found." % student_name)
		return false
	return student_records[student_name]["courses"].has(course)

func calculate_average_grade(student_name: String) -> float:
	if not student_records.has(student_name):
		print("Student '%s' not found." % student_name)
		return -1.0
	var grades: Array = student_records[student_name]["grades"]
	if grades.is_empty():
		return 0.0
	var total := 0
	for grade in grades:
		total += grade
	return float(total) / grades.size()

func list_students_by_course(course: String) -> Array:
	var students_in_course := []
	for student_name in student_records:
		if student_records[student_name]["courses"].has(course):
			students_in_course.append(student_name)
	return students_in_course